1. Technical Field
Embodiments of the subject matter disclosed herein generally relate to methods and systems and, more particularly, to mechanisms and techniques for connecting a shear blade to a shear block.
2. Discussion of the Background
During the past years, with the increase in price of fossil fuels, the interest in developing new production fields has dramatically increased. At the same time, the equipment for extracting the oil is undergoing continuous changes for becoming more effective and reliable. Due to the high price of fossil fuels, a downtime of a rig for maintenance purposes needs to be reduced. However, it is know that, for example, for opening a shear ram blowout preventer (BOP) and changing the shear blades requires the effort of a few technicians for a few hours. One of the operations that is slowing down the shear blades replacements is, among others, the need to remove large screws connecting the shear blades to corresponding shear blocks.
Such a shear ram BOP is shown in FIG. 1. A BOP 16 is shown having shear blocks 20. The shear blocks 20 are configured to move, when actuated by a rod 22, inside a first elongated cavity 24. The first elongated cavity 24 extends along a first axis X. A second elongated cavity 26 extends substantially perpendicular to and intersects the first elongated cavity 24. The shear block 20 may include a shear blade 28 that is configured to cut a tool 30 that may be present inside a well 32. The shear blade 28 may have a sharp edge that effectively cuts tool 30 when necessary. A similar shear block and shear blade may be provided in an opposite region of the first elongated cavity 24.
A more detailed view of the shear block 20 and the shear blade 28 is shown in FIG. 2. The shear blade 28 is shown detached from the shear block 20. To attach the shear blade 28 to the shear block 20, a plurality of screws 36 are used. Corresponding holes 38 are formed in a frontal face 40 of the shear block 20. The sharp edge 42 of the shear blade 28 is configured to shear the tool. The thicker the tools provided inside well 32, the more powerful shear blocks 20 and blades 28 need to be provided to resist to the high pressures present inside the BOP when cutting the tool. Such pressure may be between 2,000 and 25,000 psi. However, the holes in the shear blade and the shear block weaken the structure of these elements, making them prone to failure when the high pressures are present.
Accordingly, it would be desirable to provide systems and methods that avoid the afore-described problems and drawbacks.